From d45e1595ec1cffeab83ac6602b748250b66bea03 Mon Sep 17 00:00:00 2001
From: Sebastiano Tronto <sebastiano@tronto.net>
Date: Mon, 24 Mar 2025 23:09:26 +0100
Subject: Big cleanup for appendsolution()

With this PR the appendsolution routine is extracted from the h48
solver and the new coordinate solver and made generic. This has
many advantages:
- less repetition (even if the two versions are different enough that
  *for now* it was not a big deal)
- smaller h48/solve.h file, which is already a big beast
- easier to test the appendsolution() routine separately
---
 src/core/moves.h | 68 ++++++++++++++------------------------------------------
 1 file changed, 17 insertions(+), 51 deletions(-)

(limited to 'src/core/moves.h')

diff --git a/src/core/moves.h b/src/core/moves.h
index 820406b..e56d5c8 100644
--- a/src/core/moves.h
+++ b/src/core/moves.h
@@ -3,6 +3,7 @@
 
 STATIC_INLINE bool allowednextmove(size_t n, const uint8_t [n]);
 STATIC_INLINE uint32_t allowednextmove_mask(size_t n, const uint8_t [n]);
+STATIC bool allowedmoves(size_t n, const uint8_t [n]);
 
 STATIC_INLINE uint8_t movebase(uint8_t);
 STATIC_INLINE uint8_t moveaxis(uint8_t);
@@ -13,11 +14,9 @@ STATIC_INLINE uint32_t disable_moves(uint32_t, uint8_t);
 STATIC cube_t move(cube_t, uint8_t);
 STATIC cube_t premove(cube_t, uint8_t);
 STATIC uint8_t inverse_move(uint8_t);
-STATIC void invertmoves(size_t n, const uint8_t [n], uint8_t [n]);
-STATIC void sortparallel(size_t n, uint8_t [n]);
+STATIC void sortparallel_moves(size_t n, uint8_t [n]);
 STATIC bool are_lastmoves_singlecw(size_t n, uint8_t [n]);
 
-STATIC int readmoves(const char *, int, uint8_t *);
 STATIC cube_t applymoves(cube_t, const char *);
 
 #define FOREACH_READMOVE(ARG_BUF, ARG_MOVE, ARG_C, ARG_MAX, \
@@ -75,6 +74,18 @@ allowednextmove_mask(size_t n, const uint8_t moves[n])
 	return result;
 }
 
+STATIC bool
+allowedmoves(size_t n, const uint8_t moves[n])
+{
+	uint8_t j;
+
+	for (j = 2; j < n; j++)
+		if (!allowednextmove(j, moves))
+			return false;
+
+	return true;
+}
+
 STATIC_INLINE uint32_t 
 disable_moves(uint32_t current_result, uint8_t base_index)
 {
@@ -210,44 +221,13 @@ inverse_move(uint8_t m)
 	return m - 2 * (m % 3) + 2;	
 }
 
-/*
-GCC has issues when -Wstringop-overflow is used together with O3. It produces
-warnings like the following:
-
-In function 'invertmoves',
-    inlined from 'solve_h48_appendsolution' at src/solvers/h48/solve.h:81:3,
-    inlined from 'solve_h48_dfs.isra' at src/solvers/h48/solve.h:139:3:
-warning: writing 32 bytes into a region of size 0 [-Wstringop-overflow=]
-  197 |                 ret[i] = inverse_move(moves[nmoves - i - 1]);
-      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-In function 'solve_h48_dfs.isra':
-note: at offset 192 into destination object 'invertedpremoves' of size 20
-   71 |         uint8_t invertedpremoves[MAXLEN];
-
-Clang does not give any warning.
-Someone else complained here: https://access.redhat.com/solutions/6755371
-
-To solve this issue temporarily, we use a lower optimization setting for
-this function only.
-
-TODO check if the issue is resolved
-*/
-#pragma GCC push_options
-#pragma GCC optimize ("O2")
 STATIC void
-invertmoves(size_t n, const uint8_t moves[n], uint8_t ret[n])
+sortparallel_moves(size_t n, uint8_t moves[n])
 {
 	uint8_t i;
 
-	for (i = 0; i < n; i++)
-		ret[i] = inverse_move(moves[n - i - 1]);
-}
-#pragma GCC pop_options
-
-STATIC void
-sortparallel(size_t n, uint8_t moves[n])
-{
-	uint8_t i;
+	if (n < 2)
+		return;
 
 	for (i = 0; i < n-1; i++)
 		if (moveaxis(moves[i]) == moveaxis(moves[i+1]) &&
@@ -268,20 +248,6 @@ are_lastmoves_singlecw(size_t n, uint8_t moves[n])
 	return isbase(moves[n-1]) && (!two || isbase(moves[n-2]));
 }
 
-STATIC int
-readmoves(const char *buf, int max, uint8_t *ret)
-{
-	uint8_t m;
-	int c;
-
-	FOREACH_READMOVE(buf, m, c, max, NISSY_ERROR_INVALID_MOVES,
-		if (ret != NULL)
-			ret[c] = m;
-	)
-
-	return c;
-}
-
 STATIC cube_t
 applymoves(cube_t cube, const char *buf)
 {
-- 
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